extract_attributes

# File activerecord/lib/active_record/relation/where_clause.rb, line 105
      def extract_attributes
        predicates.each_with_object([]) do |node, attrs|
          attr = extract_attribute(node) || begin
            node.left if node.equality? && node.left.is_a?(Arel::Predications)
          end
          attrs << attr if attr
        end
      end